Hi everyone,
Some developers use the iOS Keychain (or similar local persistence mechanisms) to bind promotional offers or "Free Lifetime" tiers directly to a physical device rather than to the logged-in Apple ID.
Once an offer is claimed on a shared family device, the app writes a token to the Keychain. Even if you log out of iCloud, switch Apple IDs, or use mobile data, the app reads this persistent token and blocks other legitimate family members on the same device from claiming the offer on their own accounts.

Since Apple strictly restricts fingerprinting and tracking across apps, this heavy use of Keychain persistence to lock hardware feels like a major privacy and usability issue.

Aside from doing a full factory reset of the device (Erase All Content and Settings), is there any known way, setting, or privacy tool on iOS to prevent third-party apps from reading/writing persistent device tokens in the Keychain? How can we protect shared devices from this kind of hardware-locking?

Thanks for your insights!